I was driving home the other night and went to pass this guy (from a stop at an intersection) and took 1st gear up to 5000 or so RPM. i noticed that i had a significant drop in power after 4500 rpm. I went to test and see if it wasnt just a fluke and raced it the rest of the way home (less than a quarter mile). i couldnt get up over 4000 rpm at all and then my engine sputtered i got a "eng pwr reduced" warning on the DIC and i all of a sudden couldnt go over 2000 rpm i coasted into my driveway and couldnt get up it. i threw the E-brake turned off my balt and went inside. i looked up the problem and found that for some people the problem comes and goes. so i went outside and started it back up and got the rest of the way up the drive way (at this time it acted normal and the "eng pwr reduced" light had gone away.)
i spent the rest of the night reading thread after thread. the next day i went to go have Advance Auto Parts read the codes came back P0068 and P0171 ive had the P0171 for awhile and looks like it should have been an early sign of somthing that later on tripped the p0068.

P0068 Mass Air Flow/ Throttle Body
P0171 System to lean

After getting the codes i went home and checked the air filter. upon further inspection of the air filter housing, it was cracked and had a hole in it (about 1" in diameter). within the housing there was a little dirt/mud and a small rust spot on the metal screen but other then that the filter was in overall good shape.

any way the main symptoms im experiencing are:
-RPM's will not go over 4000
-If i try to make RPM's go over 4k it cuts RPM's down and then goes into "limp mode."
-when in "limp mode" idle rapidly spudders between 750-1250 RPM

givin p0171 im either getting to much air or not enough fuel so my TB is getting stuck open or ive got a clog in my fuel filter. so thats what im going to check today.

So what do you guy's think? am i on the right track? any advice? im at my witts end, please HELP! Thanks in advance.

 

p0171 could also mean bad gas..or bad injectors.. got the code 2 weeks ago but hasn't come back .... I would clean the TB if I were u

 

I got P0171 and it turned out to be bad gas

 

i filled up about a week ago and then i got down to half a tank, and then this happend could that mean bad gas still even though ive used half the gas in there? also ive had the p0171 code for a while (months) could it be that ive got bad gas before and it tripped the 171 code and it has never erased itself?

side note: i went to Meineke to get them to run codes months back and they told me i had the 171 code and told me changing my thermostat would fix it...

 

Found the Problem... Clogged cat.
New problem which to get...
ZZPerformance - Mid Length Header & Downpipe Combo #ZZ-MIDLHDP
?

 

U can get a free one at gm

 

You coming to our Indy meet this Saturday? I can check the car out for you if you want to come.

 

I would get a completely new air filter. I was throwing the same code p0171 and my filter was ****. Changed that and a maf and car ran well again.